In the operation of construction machines of the type known as landfill compactors, it is a common and recurring problem to have refuse packed in and around the wheels of the machine. Landfills are typically filled with many kinds of refuse, but in many sites there is an abundance of wire, metal banding and strands of other types of metal. When the machine traverses the terrain, these strips of material tend to become picked up by the teeth of the compacting wheel and entrained thereabout. The material will carry other refuse with it and the entire inner portion between the wheel and the machine can become packed with debris. This not only inhibits the oscillation of the axles and thereby adversely affecting machine performance, but it also causes the inner portions of the wheels to become prematurely worn out due to continual contact with the debris packed in and around areas adjacent the wheel. In addition, the machine must be continually removed from the site to a service area to cut the material away, and to clean the debris from around the axle. This is costly in terms of both manpower and lost production time.
One solution to this problem has been to provide a cutting mechanism between the wheel and the axle to act as a shear as the machine moves and the wheels turn. In one particular design, disclosed in U.S. Pat. No. 5,330,260, a stationary shear member is mounted to the axle housing while a second shear member is mounted to the inner portion of an adjacent wheel. The two shear members are arranged so that they pass in close proximity to one another as the wheel rotates about the axle. The material that would be entrained about the axle is severed as the two shear members pass one another.
While this system has been known to work well as a shear mechanism, the force created between the wheel and the axle has been known to be excessive. Because the two shear members are welded in place, there is virtually no "give" between the shear members and the forces created by the shearing of material are transferred directly into the axle assemblies. This excessive force could overload the axle assemblies and cause premature failure of any one of a number of components within the axle assemblies.